Robert X. Cringely thinks that Apple will offer virtualization in Mac OS 10.5, but in order to do that, he thinks Apple will need to drop Mach. "So Apple will at least offer the option for users to run a virtualized version of Windows Vista atop OS X. Don't be surprised, either, to see that OS X 10.5 has a new kernel, finally giving up Mach and a big piece of its NeXTstep heritage. I write this for one thing - because OS X has kernel problems and needs some help, especially with swap space. I say it also because of the departure of Avie Tevanian, Apple's chief software technology officer, and the guy who hung onto Mach for so long." The Mach kernel has recently been the target for complaints; esp. in server duties, OSX' kernel lags behind significantly compared to i.e. Linux.

Apple will NEVER switch to using Linux as the kernel for OSX. It's impossible, for one, single, simple reason, and I don't care if I get flamed for saying it:

GPL.

Whether people like it or not, the GPL has restrictions that do not fit into Apple's way of doing things-- that is, total control over every aspect, from the bits on your harddrive to the mouse you use to navigate the interface. This is a good thing, in my opinion, as it creates a very seamless user experience that I personally really enjoy. But with using Linux, they would have to comply with a very strict license, and they'll have millions of pairs of OSS eyes watching their every step.

Remember how Apple did not release the x86 sources to the latest Darwin releases? Do you think that is possible when they use the Linux kernel? Hell no.

Secondly, but no less important, the GPL is kind of a legal no man's land. People intepret the GPL in different ways, which means that Apple will be much more vulnerable to legal threats. And if there's one thing shareholders and investors do not like, it's legal no man's lands.

Apart from that you're spreading FUD. GPL is perfectly legal, and in no way a "kind of legal no man's land". It has so far not failed in court anywhere. And the GPL it self is pretty clear (LGPL is much more complicated).

I know how much you hate GPL and I've read the nonsense you've written on skyos.org, but puhlease... Get a grip on yourself, and start behaving properly.

I do agree though, that Apple would never use Linux as the kernel. The Linux kernel tends to evolve in too many different directions to be interesting for Apple. But this is a technical issue and not a licensing issue.

I'm not talking about whether or not the GPL can hold up in court. I'm talking about how different people intepret the GPL in different ways. THAT means it's a legal no man's land, because judge A might intepret the GPL in a different way than judge B.

I know how much you hate GPL and I've read the nonsense you've written on skyos.org, but puhlease... Get a grip on yourself, and start behaving properly.

Ah right, we get someon who read a few posts on the SkyOS boards and who thinks he knows me. Tone it down there, sonny. I've been active in that community for quite a longer time than you have, so don't act like you're some sort of expert on SkyOS.

And no, I don't hate the GPL. The license is just not suited for Apple, that's it.

Apple's way of doing things-- that is, total control over every aspect, from the bits on your harddrive to the mouse you use to navigate the interface

Thom, how does Apple control what "bits" I have on my hard drive? (By "bits" I assume you mean my files and programs?)

And how does Apple control what mouse I use to navigate the Interface?

I don't understand this "total control" myth. I can use any brand of notebook harddrive in my Mac mini, any brand of RAM, any brand of monitor, speakers, microphone, mouse, keyboard, and printer. Apple does not get to make those decisions for me. They may provide me with their defaults, but they in no way prevent me from using something else.